Duplex receptacle



Dec. 16, 1930. HQL. STRONGSON DUPLEX RECEPTACLE Filed Oct. 19, 1925 2 Sheets-Sheet l INVENTOR //ermam L zrangsan.

BY I 1" ATTORNEY} Patented Dec. 16, 1930 UNITED STATES HERMAN L. s'rnoneson, on NEW YORK, N. Y.

DUPLEX RECEPTAOLE Application filed October 19, 1925. ser al No. 63,235.

This invention relates to electric outlet fixtures and more particularly to contact mechanism in general associated with outlet boxes and wall finish plates therefor.- To

illustrate the principle of my invention, I will among other things disclose an improved wall plate receptacle.

A'main purpose of the invention is to simplifyelectrical installation work in building construction, particularly in the wall outlet whether for wall switches, push buttons, base or wall receptacles, lighting fixtures or other-- wise. To this end I reduce the number of parts ordinarily used in assembling a coml5 plete wall outlet box assembly, not only this but my invention leads the way to improvements in the structure, the operation and the appearance of parts employed, particularly the wall finish or cover plate, and provides a two-part box assembly instead of three as now commonly in use. I

Present day standard practice in installing electrical outlets in a building wall require the use of an outlet box, a contact mechanism I such as a switch or a lug-in receptacle block mounted within the ox, and finally a wall finish flush cover plate mounted thereover, the said assembly comprising three separate parts.

39 Among the several objects of my invention, one purpose is to eliminate the foregoing separate contact mechanism and combine it with the wall plate. In other words,

I improve the wall plate and the contact mechanism by combining them into one part so that the function of the wall plate is not only to cover the outlet box in the wall as of old but an additional and new function thereof is to carry and support the contact mechanism as well. In this way, the work of installation is much simpler. Furthermore, it is in general, much neater in appearance.

I accomplish the foregoin purposes and others by building in or mol ing in the con- .tact mechanism on the rear side of the wall plate so that the heretofore two separate units now constitute one and the same part.

'One purpose is to produce an 1m roved wall receptacle which is constructed 1n conjunction or-combination with the wall late as aforesaid. The contact mechanism consistingof the two well known yieldable con tact blades against which is slipped the jack blades of a removable plug connector cap) is' set or molded into a frame or housing on the rear face of the wall plate. This combination economizes in material because the wall cover plate is; essential in any event, and so I largely save the molded material heretofore used in the manufacture of the separate contact mechanism receptacle block, The combina tion is'neat in appearance because my wall plate does not require a large aperture therethrough for exposure of and accessibility to the plug-in receptacles.

Another object is to produce a plural base receptacle of compact design and construction which affords two or more electrical outlets made in one wall plate and housed in one outlet box.

The accompanying drawings illustrate preferred forms of the invention showing an embodiment of the structure and certain changes may of course be made without departing from the principles involved. The principle of the invention may be adapted to the manufacture of various improved toggle and button switches and other circuit and contact I making devices which are ordinarily required to be concealed behind a wall finish plate within an outlet box.

Figure '1 shows a front or face view of the new'combination wall outlet box and finish plate therefor and plug-in electric receptacle. p

The receptacle plate shown is a duplex or tworeceptacle outlet but a wall plate of any number of outlets may be manufactured iIi accordance with the plans of this invention.

Figure 2 shows a longitudinal sectional view as taken on the line 2-2 of Figures 1 and 3, and illustrates a longitudinal sectional view of the composite wall plate and plug-in receptacle, and to better illustrate its application to wall installations, it is placed'over and within an ordinary outlet box B.

Figure 4 illustrates a rear sectional view taken on the line 4-4 of Figure 2 which again illustrates the combination wall plate and base receptacle installed over and within the outlet box.

Figure 5 shows the base receptacle Wall plate in cross section. An ordinary electric jack blade plug cap connector C on the end of a flexible wire connection F, is shown plugged through the plate into the receptacle merely to illustrate how my wall plate receptacle lends itself to conventional-practice.

Figure 6 shows a separate enlarged detailed view of an improved contact member used in the make-up of the wall plate receptacle.

Figures 7 to 13 illustrate a modified form of base receptacle of still simpler structure than that shown in the former views.

Figures 7 to inclusive show progressive views of an improved modified form of electrical conductor or circuit bars used in the manufacture of plural base receptacles;

Figure 7 showing the method of stamping two bars which are identical in structure from sheet metal; Figure 8 showing an end projection of one of the stamped parts; Figure 9 being an end view of one of the stamped parts after it is finally formed and fashioned with its one or more upstanding spaced contact blades; and Figure 10 showing a plan view of the completed bar and its contact blades. This circuit bar is des gned for use in connection with the plural base receptacle in Figures 11. 12 and 13.

Figure 11 shows a cross sectional view as taken on the line 1111 of Figure 12 and illustrates the assembly of two circuit bars on or in a wall plate to produce the improved fixture in question; Figure 12 shows a full rear view thereof; and Figure 13 shows a side view thereof.

Figure 14 shows still another modified and improved form of circuit or conductor bar with a, plural number of integral contact blades. This particular circuit bar has its contact blades so designed and constructed as to enable the manufacturer to produce what is ordinarily called tandem slot plug-in receptacles. 7

Referring now more particularly to the accompanying drawings for a detailed description of the invention, the improved wall or base plate 15 is made or molded integral with a frame, receptacle, housing, casing, or boss means 19 or insulation blocks 19 on the rear face thereof for the purpose of supporting and 1 concealing the contact mechanism, whatever the character thereof be. In the present case the'means 19 simply consists of a boss or housing to receive and house or cover the contact blades of a plug-in base or wall receptacle, while in other cases the means 19 on the wall plate 15 is alteredin form to accommodate a switch, a press button, or other contact makeand-break mechanis The wall outlet or base receptacle plate 15 is provided With any suitable number of plugin slot receptacles 16 arranged in cooperating pairs, the pair of slots 16 being spaced from the pair of slots 17, each pair being adapted to receive the jack blades E of an ordinary plug cap-C on the end of a flexible cord F Figure 5. My improved wall plate outlet 15 is capable of providing several outlet slots for the reception of standard flexible cord connections FC. The spaced apertures 16 are usually molded in the plate 15 and extend through the plate and through the boss, housing or frame means 19 on the rear face thereof. However it is clear enough that my improved principle, while well adapted to molding operations to integrally form the wall finish plate 15 with the boss 19 and in order A that this composite structure be of molded insulation, may also be adapted to separate construction and to metal construction. In other words, the two parts 15'and 19 may be made of metal, and may be made separately and then joined together, but molded insulation is preferred.

The wall plate 15 is made with the casing or housing boss 19 on the back side thereof for the purpose of concealing and holding the contact mechanism or circuit make-andbreak means whether that mechanism be a switch, or ordinary plug-in receptacle, or switch button mechanism, fuse holder, cable conduit or wire attachment means, or otherwise; the main point being in fact that the mechanism itself of whatsoever nature, be

concealed within and carried by the wall plate 15 as opposed to being separated therefrom so characteristic of present-day standard practice. Hence the box cover and elec trical contact means constitute a single unit which is capable of being mounted and removed from an outlet or junction box B to simplify installationand reduce the number of parts to be handled.

To the above ends and others, the said wall plate 15 is made with any suitable number of bosses or housing means 19 molded or otherwise made on the rear face of the wall plate 15. .In the present case, there being two sets of outlet apertures or slots 16 and 17, there is provided an equal number of bosses 19 and 20 which are spaced apart and which act as the foundation, or housingto support and hold the contact mechanism in service position. One boss or mounting means 19 or 20 is employed in the manufacture of single wall plate outlets where that-is desired, but in the drawings there is described as a matter of convenience a multiple base receptacle wall plate. In fact, the two bosses 19 and 20.may if desired be merged or simply run together thereby forming one continuous boss on the back of the plate 15, but the two spaced bosses require less material and ,produce a light weight product. The wall finish plate 15 spreads across the housing or boss means tects all contact making mechanism associated with the plate. v

Reference is now made to Figure 6 which illustrates an enlarged sectional view of one practical form of contact member which functions satisfactorily with jack blades Eof standard removable plug caps C. The contact member illustrating my invention comprises a straight vertical stem 22 with a downturned flexible contact blade 23. The blade and stem 2223 are integrally made on a T-head comprising a lower horizontal base 24 and upper flexible rests 25.

One of these Figure 6 contact members is thrust in each receptacle slot 16 and 17 with the flexible rests thereof thrust up against the back surface of the boss 20. This arrangement disposes the flexible contact blade 23 in a slot 16 and next a circuit or conductor bar 26 is mounted againstthe base 24 as shown in rear view Figure 4 and this bar 26 presses against the base 24 of the contact member with the result that it is firmly held in position in the slot 16 or 17 without the aid of any screw;-5,-rivets or other securing means. Effective electrical contact is established between the bar 26 and the several contact members because the bar bears firmly thereagainst by reason of screws, eyelets or rivets 27 which anchor the bar in position on the bosses 19 and 20.

A circuit bar 26 is common to as many contacts 24 as are required to make up a plural wall plate receptacle, and a pair of the aforesaid bars 26 is used in the construction of the improved base receptacle plate, the two bars being spaced apart in parallel relation and conventional metal inserts 28 may be molded in the block or boss portion 19 and 20 to receive the screws 27. The spaced bars 26 extend lengthwise of the plate 15 and bridge from one boss 19 to the other 20 or bridge across as many bosses as may be made on the back of the plate 15. Each bar 26 is provided with suitable connecting means for wires and to this end a screw 29 is mounted in each bar 26 for the purpose of being tightened down on the bare skinned end of electrical wire connections (not shown) brought into the outlet box B.

For a full understandin of the invention,

I have shown my improve combination base receptacle wall plate mounted over'an ordinary electric fixture, outlet box B and those conversant with the art will understand how the outlet box B is made with cable receiving holes H for the purpose of leading electric feed wires into the box B to the point of use. The present day practice of electric installation work requires the use of the box 13, andelectric fixture block in the nature of contact meanssuch as a switch or plug-in receptacle not shown, together with a simple flat" wan finish plate; there bein three parts in all, but as already mentione at the outset, the adoption of my invention requires the use of only two parts, namely, the standard electric fixture or outlet box B together with my combination wall plate 1 thereby eliminating one part and simplifying electric installation work in the Walls of houses and the like. The contact parts or mechanism on the rear side of the Wall plate are confined in the outlet box B, and is held in spaced insulated position therefrom which improves greatly the character of the work.

The modified and improved form of base receptacle electric fixture shown in Sheet 2 of the drawings will now be described.

Referring first to Figures 7 to 10 for a description of an improved circuit bar carrying a plurality of integral contact blades, there is shown a stamped sheet metal circuit or conductor bar 31 with apertures 32 for the reception of eyelets or other anchoring means to fasten the'bar to the wall plate 33. The bar 31 is punched with outstanding spaced contact blades 34 of any suitable number. The contact blades 34 are fashioned into upstanding position as shown in Figure 9 and one edge of the bar 31 is upturned to form a bead or'longitudinal stiffening rib 35 which imparts stiffness to the long bar 31. Figures 9 and 10 show the finished circuit bar and it may be stamped from light gage sheet metal in order that the resulting contact blades 34 be light in weight, flexible and susceptible to the contacting engagement of jack blades of plug caps which ar thrust thereagainst.

The combination integrally molded wall plate 33 and boss 36 is made with a pair of receptacle slots 38 reaching therethrough for the reception of jack blades or prongs of an ordinary plug connector cap. -Theslots 38 are duplicated at regular intervals where it is desired to make a plurality base receptacle. For example another pair of receptacle slots 39 is made or molded in and through the wall plate 33 and boss 37. The receptacle passages 38 and 39 are suitably spaced apart to enable each one to conveniently receive a plug-in cap connector of ordinary household use.

The flexible contact blades 3 10f the circuit bar 31 heretofore described are spaced apart equal tothe distance between one slot 38 and the,other slot 39 and two bars 31 are installed on the rear face of the wall plate with the contact blades 34 lying concealed within the several receptacle slots 38 and 39. Two circuit-bars 31 are required to make up the wall plate and the bars are placed para lel in spaced relation and are anchored in grooves 41 molded in the rear face of the bosses 36 and 37. vEyelets'or other suitable anchorage means 42 secure the bars 31 in place. Each bar 31 carries a screw 44 threaded thereinto for the purpose of establishing electric wire connections (not shown) with lift the two bars to furnish a source of electric and 39.

Referring now to the Figure 14 views there is illustrated an improved form of circuit bar with integral contacts designed for the purpose of enabling the manufacturer to produce wall receptacle plates having what is ordinarily called tandem plug-in receptacles for plug cap connectors. These views show progressive operations in the manufacture of a tandem slot wall receptacle circuit bar. It is manufactured by stamping from sheet metal a lightweight flat piece 46 having a hole 47 at each end by which the bar is anchored to a molded wall plate of the same design as heretofore described except for the receptacle slots. The'stamped part 46 is sheared and cut to provide upturned flexible contact blades 48. One or more lengthwise edges of the bar 46 are 'crimped to produce a stiffening rib 49 extending longitudinally of the bar.

The several contact blades 48 are designed to face each other. By employing two circuit bars 46 side by side, it follows that two contact blades 48 are mated to produce one com-i plete set of contacts for a plug-in receptacle or outlet and thereby aflord a satisfactory structure for producing tandem receptacle slots for base receptacles in multiple formation. v

The wallplate receptacle herein described carriesthe contact mechanism as a part thereof and the installation of the wall plate over the outlet box in electrical Work means that the job is completed, it is neater, it comprises fewer parts. Furthermore, no separate insulator sheet orlmeans is required between the box and fiat cover plate.

My improved two-part combination outlet box and one-piece wall plate contact mechanism is assembled'more quicklythan the old three-piece combination now in use. Furthermore, it is evident that the contact mechanism is inherently insulated from the steel-box B and spaced centrally in the box with a large amount of clearance space left in the box for the reception of surplus wire length needed by the mechanic when he is working on the box assembly'in the wall of a building.

What I claim is:

1. A wall outlet of the multiple receptacle type comprising, a plate of. insulation forming an outlet box cover and provided with a plurality of plug-in receptacle slots made therethrough, contact blades disposed and held within the receptacle slots, a housing of insulation material on the back of the plate and. surrounding each contact blade, and a circuit bar disposed to the. rear of the housing and connected with the contact blades.

2. An electricalwall outlet device adapted to supply current to a plurality of jack blade behind, each boss madewith receptacle slots therein which extend through the plate, a pair of spaced circuit bars reaching from one boss'to the other and anchored to the bosses, and a contact blade mounted in each receptacle slot and connected with a circuit bar.

4. A multiple receptacle outlet comprising, a wall finish plate, a plurality of bosslike housings disposed in spaced relation on the rear face of the plate, said plate and housings made in one integral piece of molded insulation, pairs of receptacle slots made through the molded plate and extending into the molded housings, a pair of circuit bars disposed in parallel relation and bridging the space between the plurality of boss-like housings and overlying the aforesaid receptacle slots, and a contact blade extending flrom each circuit bar into each receptacle s 0t.

5. A multiple receptacle outlet comprising, a wall finish plate, a plurality of bosslike housings disposed in spaced. relation on the rear face of the plate, said plate and housings made in one integral piece of molded insulation, pairs of receptacle slots made through the molded plate and through the molded housings, a pair of circuit bars bridging the space between the housings from one to the other, and contact blades associated with the bars which blades are held .in the slots by said bars.

6. A multiple receptacle outlet compris-'- ing, a wall finish plate. a plurality of bosslike housings disposed in spaced relation on the rear face of the plate, said plate and housings made-in one integral piece of molded insulation, pairs of receptacle slots made through the molded plate and through the molded housings, a pair of circuit bars reaching from one housing to another, a contact blade disposed in each slot, and a base portion made on one end of each contact blade and pressed and engaged by acircuit bar.

7. A duplex receptacle comprising a relatively thin face plate of insulating material provided at its inner face with spaced inwardly projecting enlargements having.

slots for the reception of knife contacts, spring contacts arranged within the slots of the enlargements, transversely spaced longitudinally disposed conductor -bars bridging the intervening space between the located in the said intervening, space.

9. An electrical outlet assembly limited to a two-part combination for ordinary house wiring, a box to receive feed-wire terminals, a flat. plate of insulation material disposed over the box and forming a suitable thin cover therefor, an insulation boss carried on the rear face of the insulation plate, said insulation plate and boss being provided with spaced receptacle slots opening thru the outer face of the plate, electrical contact means mounted in the slots back of the flat plate, and feed-wire connectiommeans to attach wire terminals to the electrical contact means, I

10. An electrical outlet receptacle comprising a fiat insulation cover plate having a fiat .front and rear face and adapted to be disposed over a box and be insulated there from, an insulation boss carried on the rear face of the plate, said insulation plate and boss being provided with duplex receptacle slots therein which open straight thru and perpendicular to the face of the plate and thus aflord a plural electrical outlet, contact means in the slots adapted to be engaged by contact blades on a ,removable plug cap, and clamp-screw means by which terminal wires may be attached to the contact means.

11. An electrical plug-in receptacle comprising, an insulation member having reeeptacle slots therein formed to receive'contact blades of a removable plug cap and said slots a bar and wire connecting means anchored against the base portion end of the stem.

12. An electrical outlet comprising an insulation plate forming a thin flat cover for outlet boxes and made with plug-in electrical receptacle slots which open perpendicularly thru said flat cover, a boss of insulation material carried on the rear face of the insulation'plate and also made with plug-in receptacle slots which form a continuation of the first named slots, contact means housed in the boss behind the plate including a contact blade mounted'in each slot to the-rear of the fiat cover, and wire connection means carried on the boss of insulation and connected with-the contact means.

13. A multiple receptacle outlet as defined in claim 6; further characterized by making the contact blade of T-shaped form with a base portion, and said base portion being anchored between the circuit bar and face of the housing.

14. Contact, members fora receptacle of" the character defined in claim 6,"comprising a stem, a flexible contact blade integral therewith 011 one end of the stem, a base portion made on the other end of the stem thereby forming a contact having a resilient stem and a resilient base portion, and which is of general T-shaped construction.

15. An electrical outlet device to cover a box and comprising an insulation face plate of thin flat formation of larger surface area than the box adapted to be closed thereby, spaced insulation housing means integral with and projecting from the rear surface of the insulation face plate and forming therewith a unitary construction,

said insulation face plate being provided with spaced pairs of receptacle slots opening straight thru the plate and into the insulation housing means, conductor bars attached to the rear of the insulation face plate and having integral upstanding contacts within the housing means, said integral contacts being located at each end of each conductor bar and in alignment with and extending toward the receptacle slots of the insulation face plate aforesaid, said contacts having curved flexible end portions terminating behind the rear surface of the insulation face plate, and electrical-wire connecting means provided on each conductor opening thru one face of the insulation membar.

' ber, contact partsmounted in the slots and each part including a stem, one end of which stem is bent back to form a flexible contact and the other end being formed with a base portion which is disposed at that end of the slot which is opposite the end of the slot which opens thruthe face of the insulation member, said base portion including flexible depressible portions substantially parallel to 'each other and formed by bending theend of the stem at right angles upon itself, and

In testimony whereof I afiix my signature.

HERMAN L1 STRONGSON.

DISCLAIMER 1,785,463.Hcrmun'L. Strongson, New York,-N. Y. DUPLEX, RECEPTXCLE. Patent dated December 16, 1930. Disclaimer filed February 5, 1932, by Carl F. Siemon, receiver of T he Connecticut Electric Manufacturing Co.

Your petitioner, therefore, herebylenters this disclaimer to claims 1, 2, 9, 10 and 12 in said patent, which are in the following words, to wit:

1. A wall outlet of the multiple receptacle type comprising, a plate of insulation forming an outlet box cover and provided with a plurality of plug-in receptacle slots made therethrough, contact blades disposed and heldwithin the receptacle slots, a housing of insulation material on the back of the plate and surrounding each contact blade, and a circuit bar disposed to the rear of the housing and connected with the contact blades. 4

2. An electrical wall outlet device adapted to supply current to a plurality of jack blade plug cap connectors, comprising in combination, a wall finish insulation-plate, housing means of insulation formed integrally on the rear face thereof, contact blades mounted in spaced pairsin the housing means, a pair of circuit bars anchored to the housing means and connected with said contact blades, and said plate provided with receptacle slots made therethrough arranged in spaced pairs reaching to the housing means and to the contact blades.

9. An electrical outlet assembly limited to a two-part combination for ordinary house wiring, a box to receive feed-Wire terminals, a flat plate of insulation material disposed over the box and forming a suitable thin cover therefor, an insulation boss carried on the rear face of the insulation plate, said insulation plate and boss being provided with spaced receptacleslots opening thru the outer face of the plate, elec trical contact means mounted in the slots back of the flat plate, and feed-wire connection means to attach wire terminals to the electrical contact means.

10. An electrical outlet receptacle comprisinga fiat insulation cover plate having a flat front andrea'r face and adapted to be disposed over a box and be insulated therefrom, an insulation boss carried on the rear face of the plate, said insulation plate and boss being provided with duplex receptacle slots therein which open straight thru and perpendicular to the face of the plate and thus afford a plural electrical outlet, contact means in the slots adapted to be engaged by contact blades on a removable plug cap, and clamp-screw means by which terminal wires may be attached to the contact means.

12.- An electrical outlet comprising aninsulation plate forming a thin flat cover foroutlet boxes and made with plug-in electrical receptacle slots which open perpendicularly-thru said flat cover, a boss of insulation material carried on the rear face of the insulation plate and also made with plug-in receptacle slots which form a continuation of the first named slots, contact means housed in the boss behlnd the plate including a contact blade mounted in each slot to the rear of the flat cover, and wire connection means carried on the boss of insulation and connected with the contact means.

[Ofiicial Gazette March 15, 1.932.] 

